Scalable edge node

ABSTRACT

A scalable edge node for servicing different video content simultaneously using two or more servers and for load balancing between the servers. Additional servers may be added or removed as the client demand serviced by the edge node changes. The node further includes a storage device that is shared between the servers, avoiding the need for multiple storage devices. The invention avoids prior architectures designed with a fixed number of servers and/or various other edge node elements, which are either too many or too few, and therefore become uneconomical or overwhelmed over a range of client demands.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from the following fifteen provisionalUnited States Patent Applications:

Ser. No. 60/275,779 entitled INTEGRATED NETWORK MANAGEMENT SYSTEM USINGHARMONIC ELEMENT MANAGERS IN A CONTENT DELIVERY SYSTEM filed on Mar. 13,2001;

Ser. No. 60/275,780 entitled FILE NAMING SYSTEM WITH TRACKING ANDDIAGNOSTIC FEATURES IN A CONTENT DELIVERY SYSTEM, filed on Mar. 13,2001;

Ser. No. 60/275,781 entitled ARCHITECTURE FOR DELIVERING VIDEO AND OTHERCONTENT AT HIGH BANDWIDTHS USING NOCs, SATELLITES, AND EDGE NODES TOINTERNET USERS, filed on Mar. 13, 2001;

Ser. No. 60/275,782 entitled MOBILE NODE FOR SATELLITE BASED CONTENTDELIVERY SYSTEM, filed on Mar. 13, 2001;

Ser. No. 60/275,783 entitled EDGE NODE ARRANGEMENT IN A SATELLITE BASEDCONTENT DELIVERY SYSTEM FOR INTERNET USERS, filed on Mar. 13, 2001;

Ser. No. 60/275,804, entitled SCALABLE IP ADDRESSING SCHEME FOR MULTIPLENOCs AND EDGE NODES, filed on Mar. 13, 2001;

Ser. No. 60/275,813 entitled DEMONSTRATION NODE IN A SATELLITE BASEDCONTENT DELIVERY SYSTEM, filed on Mar. 13, 2001;

Ser. No. 60/275,815 entitled GLOBAL OR MULTIREGION CONTENT DELIVERYSYSTEM AND METHOD USING NOCs AND ADAPATED EDGE NODES, filed on Mar. 13,2001;

Ser. No. 60/275,816 entitled END TO END SIMULATION OF A CONTENT DELIVERYSYSTEM HAVING A NOC, SATELLITE, AND EDGE MODE ARCHITECTURE, filed onMar. 13, 2001;

Ser. No. 60/275,817 entitled LARGE EDGE NODE FOR SIMULTANEOUS VIDEO ONDEMAND AND LIVE STREAMING OF SATELLITE DELIVERED CONTENT, filed on Mar.13, 2001;

Ser. No. 60/275,825 entitled MOBILE NOC FOR SATELLITE BASED CONTENTDELIVERY SYSTEM, filed on Mar. 13, 2001;

Ser. No. 60/275,826 entitled SCALABLE EDGE NODE WITH ACCESS TO SHAREDDRIVER IN A SATELLITE BASED CONTENT DELIVERY SYSETM, filed on Mar. 13,2001;

Ser. No. 60/275,827 entitled NOC ARCHITECUTRE IN A HIGH BANDWIDTHSATELLITE BASED VIDEO DELIVERY SYSTEM FOR INTERNET USERS, filed on Mar.13, 2001;

Ser. No. 60/275,838 entitled FORWARD CACHE MANAGEMENT BETWEEN EDGE NODESIN A SATELLITE BASED CONTENT DELIVERY SYSTEM, filed on Mar. 13, 2001;and

Ser. No. 60/275,795 entitled MICRONODE IN A SATELLITE BASED CONTENTDELIVERY SYSTEM, filed on Mar. 13, 2001.

The entirety of each of the preceding provisional United States patentapplications are incorporated by reference herein.

This application is related to the following thirteen co-pending UnitedStates utility patent applications that were all filed by inventorsVivian Pecus, Christopher Benden, David L. Bullock, Philip Lausier, MarkKalmbach, and Aaron D. Falk on Sep. 20, 2001 together with thisapplication:

The United States utility patent application Ser. No. 09/960,650,entitled ARCHITECTURE FOR DELIVERING VIDEO AND OTHER DATA AT HIGHBANDWIDTHS;

The United States utility patent application Ser. No. 09/960,645,entitled NETWORK OPERATION CENTER ARCHITECTURE IN A HIGH BANDWIDTHSATELLITE BASED DATA DELIVERY SYSTEM FOR INTERNET USERS;

The United States utility patent application Ser. No. 09/960,843,entitled EDGE NODE ARRANGEMENT IN A SATELLITE BASED CONTENT DELIVERYSYSTEM FOR INTERNET USERS;

The United States utility patent application Ser. No. 09/960,605,entitled LARGE EDGE NODE FOR SIMULTANEOUS VIDEO ON DEMAND AND LIVESTREAMING OF SATELLITE DELIVERED CONTENT;

The United States utility patent application Ser. No. 09/960,641,entitled INTEGRATED NETWORK MANAGEMENT SYSTEM;

The United States utility patent application Ser. No. 09/960,263,entitled MOBILE NETWORK OPERATION CENTER FOR SATELLITE BASED CONTENTDELIVERY SYSTEM;

The United States utility patent application Ser. No. 09/960,602,entitled SELF-CONTAINED DEMONSTRATION NODE IN A SATELLITE BASED CONTENTDELIVERY SYSTEM;

The United States utility patent application Ser. No. 09/960,249,entitled SCALABLE IP ADDRESSING SCHEME FOR MULTIPLE NOCS AND EDGE NODES;

The United States utility patent application Ser. No. 09/960,637,entitled MOBILE NODE FOR SATELLITE BASED CONTENT DELIVERY SYSTEM;

The United States utility patent application Ser. No. 09/960,622,entitled GLOBAL OR MULTIREGION CONTENT DELIVERY SYSTEM;

The United States utility patent application Ser. No. 09/960,649,entitled MICRONODE IN A SATELLITE BASED CONTENT DELIVERY SYSTEM;

The United States utility patent application Ser. No. 09/960,270,entitled IMPROVED FILE NAMING SYSTEM WITH TRACKING AND DIAGNOSTICFEATURES IN A CONTENT DELIVERY SYSTEM; and

The United States utility patent application Ser. No. 09/960,636,entitled FORWARD CACHE MANAGEMENT BETWEEN EDGE NODES IN A SATELLITEBASED CONTENT DELIVERY SYSTEM.

This application is also related to the following United States utilitypatent:

U.S. Pat. No. 6,886,029, entitled END TO END SIMULATION OF A CONTENTDELIVERY SYSTEM.

Each of the preceding fifteen United States utility patent applicationsare incorporated by reference herein.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent files or records, but otherwise reserves all copyrightrights whatsoever.

FIELD OF THE INVENTION

This invention relates to a method and system for delivering multimediadata to internet users at high bandwidths using a satellitecommunication link or links.

BACKGROUND OF THE INVENTION

As the popularity of the internet increases, there is a commensurateincrease in the need to deliver content over large distances throughcongested, slow internet connections. This problem is particularlycritical for files that must be delivered in a real time or near realtime sequence, such as audio and video files, and for files that must bedelivered at the same time to a multiplicity of places.

Additionally, there is a convergence of television/radio broadcast andinternet data transmission, using streaming. The dividing line betweencomputer technology and television/radio broadcast is rapidlydiminishing. “Streaming” refers to transmitting video and audioinformation via the internet to personal computers in the home andoffice environment such that the information may be viewed or heard, orboth, as it is being received. Currently, over 100,000 websites and over60% of top entertainment, sports and news sites stream content throughthe internet.

The streaming experience in the internet, however, generally has been adisappointment for viewers until now. Choppy, postage-stamp sizedimages, and bad buffering due to the congestion and packet loss ofland-based internet networks have been major obstacles for streamingmultimedia through the internet. Early attempts at streaming video andaudio have been marred by low bandwidth internet connections and networkcongestion. For example, the average stream traverses 20 hops throughloosely managed public peering points before reaching end users.Congestion on the internet routers delays delivery of streaming media tothe final destination, resulting in choppy, disjointed video.

Recent advances in last mile service providers have made high speedinternet access available to the general public through the use ofdigital subscriber line (DSL), ISDN, cable modem and satellite modemtechnology. As the technology becomes more affordable and mature, mostinternet access can be expected to be high speed solving the lowbandwidth problem of internet connections by internet users. However,the network congestion problem has not been improved as expected becauseinternet backbone routing systems have not caught up with the drasticincrease of internet traffic.

BRIEF SUMMARY OF THE INVENTION

The above-identified problems are solved and a technical advance isachieved by a system of internet broadcasting in which multimediacontent is delivered to internet users bypassing most internet backbone.

An exemplary system includes: a NOC for receiving the multimedia contentfrom the content provider and for modifying the format of the multimediacontent into a first streaming format and a format suitable forsatellite transmission; and an edge node, having a satellitecommunication link with the NOC and a direct connection to a last mileservice provider that provides internet connection to the internet user,where the edge node receives the modified multimedia content from theNOC via the satellite communication link and delivers the modifiedmultimedia content to the internet user via the last mile serviceprovider according to a second streaming format that is compatible withthe first streaming format. In an embodiment of the invention, thesecond streaming format is identical to the first streaming format.

Furthermore, the edge node of the system described above is scalable andmay include a variable number of media servers connected to a loadbalancer, where the load balancer is capable of determining which of theservers connected to it is best able to meet a user's request forcontent. The number of media servers is capable of being changed, whilecontent is being received, to meet changes in demand for data. The edgenode also may include a shared storage device connected to the mediaservers, and a private VLAN that receives content from the NOC over thesatellite link and distributes it to the shared storage device.

Other and further aspects of the present invention will become apparentduring the course of the following detailed description and by referenceto the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram that shows a high-level overview of an internetbroadcast network of the present invention;

FIG. 2 is a diagram that illustrates the end to end connections of aninternet broadcasting network of the present invention;

FIG. 3 is a flow chart illustrating an exemplary process of the presentinvention;

FIG. 4 is a block diagram showing an exemplary network operation centerof the present invention;

FIG. 5 is a block diagram showing functional components that maycomprise an exemplary edge node of the present invention;

FIG. 6 shows an edge node rack configuration used in the presentinvention;

FIG. 7 is a block diagram that shows a structure of an exemplary edgenode of the present invention;

FIG. 8 is a flow chart illustrating an exemplary process of the presentinvention by which a data manager of a controller of edge node operatesupon receiving packets from a network operation center; and

FIG. 9 is a flow chart illustrating an alternative exemplary process ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The method and system of the present invention regard an internetbroadcast network in which multimedia content is delivered from contentproviders to internet users without degradation. The internet broadcastnetwork allows the content providers to bypass most internet congestionpoints by utilizing a hybrid of satellites and powerful land-based edgenodes of the internet broadcast network.

Streaming video and audio in the internet enable end users to receiveand display or listen to multimedia content that are being broadcast inreal time via the internet. It is different from file transfer servicesin that it is not necessary for the end users to receive the entiretransmission before initiating playback on a personal computer. It ismost similar to broadcast television and radio services, except that thedelivery medium is the internet.

Multimedia content (e.g., movies, news, weather, sports, etc.) preparedby a content provider and ready to transmit via the internet are firstreceived at a NOC of the internet broadcasting network. The multimediacontent may or may not be an IP format. However, if the content is notin an IP format, the NOC may convert the content into an IP format.After processing, the NOC sends the multimedia content to a land-basededge node via a satellite link, thereby bypassing internet backbone,which usually causes congestion. The edge node is connected to a lastmile service provider which has internet connections to end users (e.g.,DSL, ISDN, cable modem, wireless modem, etc.). After reception,multimedia content is streamed from the edge node to the internet users'computers through the last mile service provider.

The following three services are basic services that the internetbroadcasting network (“IBN”) may offer to the content providers and endusers: (1) a continual streaming service for continuous internetstreaming applications, such as a whole day's news feed. IBN transportscontent from the source location to one or more of satellite broadcastgateways of NOC. The content is then broadcast to locations specified bythe content provider; (2) special events and regular scheduled streamingservice includes the initial internet broadcast of an event and extendsto post event servicing of on-demand streams. Streams may be requestedby individual users after an event has occurred and while demand remainshigh. The period of time for when an event will be available to userswill be specified by the content providers or last mile serviceproviders (“LMSPs”). This service is for live, one-time, short-term, andregularly scheduled streams such as sporting events and concerts; and(3) on-demand streaming is used for streams, such as music videos, videoor audio clips, internet films, and downloadable files.

The method and system of the present invention provide internet userswith high fidelity streaming multimedia content without degradationcaused by clogging and delaying from the internet backbone. Internetusers connected to one of the LMSPs would receive high quality streamingmultimedia data with the internet broadcasting network of the presentinvention.

Overall Architecture

FIG. 1 shows a high-level overview of the internet broadcast network(“IBN”) 10 of the present invention, illustrating the overallrelationships between the network elements. IBN 10 may comprise acontent provider (CP) 100 (although many content providers can be linkedto this network), a virtual network (VN) 200, a network operation center(NOC) 300, a satellite 400, an edge node (EN) 500, and a back channel(BC) 600. Multimedia content generated by CP 100 is sent to NOC 300 viaVN 200. The content is processed in NOC 300 and uploaded to satellite400. Subsequently, satellite 400 downloads the content to EN 500. EN 500is connected to a last mile service provider (LMSP) (not shown) such asa DSL, ISDN, cable modem, wireless modem, POTS, or any other type ofinternet Service Provider (“ISP”). The downloaded content in EN 500 maybe delivered to end users (e.g., subscribers to CP 100) connected to theLMSP, e.g., with a high bandwidth link, thereby bypassing most of theinternet backbone that may cause delay. BC 600 is a secondary land-basedcommunication link for a back up between and NOC 300 and EN 500. BC 600may be used for remote control of EN 500 by sending control messagesfrom NOC 300 or sending control signals from EN 500 to NOC 300.

Content Provider

CP 100 provides multimedia content to NOC. CP 100 may include anyfacilities necessary for it to function as a source of any type ofmultimedia content desired, including facilities for creating multimediacontent or storing multimedia content, or both. Multimedia content canbe any kind of data currently transmitted via television, radio, or theinternet. Exemplary content includes news and weather channels, movies,broadcast network TV, and sports prepared by CP 100. Where it is desiredto distribute multimedia content corresponding to a live event, CP 100may include media creation facilities, such as a television or radiostudio or mobile equipment for broadcasting live events at a location,e.g., a sports event, on-location news report, etc. Where the multimediacontent is not live, e.g., previously recorded movies or programming foron-demand viewing, CP 100 may include facilities for storing themultimedia content, e.g., such as video or audio tape or digital storage(e.g., magnetic hard disks, DVD, etc.) on a computer server.

If desired, CP 100 may also include facilities for transmitting thecreated or stored multimedia content which may be any type oftransmission facility capable of transmitting the desired content, suchas links to a communication network (e.g., for transmitting on-demandvideo stored on a server), equipment for satellite transmission (e.g.,for transmitting live media content), etc. However, such transmissionfacilities need not be used, such as circumstances, as described below,where multimedia content is delivered a third party carrier.

CP 100, as a customer to IBN 10, benefits from this invention byobtaining another means to deliver multimedia content to subscribers(e.g., end users) by increased advertising revenue included in thecontent, and possibly a pay-per-view or subscription revenue streams.While CP 100 could be similar to the current television and cablebroadcast networks, there will be new content providers that arestrictly web based.

Virtual Network

VN 200 represents a communication path between CP 100 and NOC 300 fordelivering multimedia content. VN 200 may comprise any kind ofcommunication link, including, for example, satellite and terrestrialvideo networks, internet or dedicated private data links, or even a3^(rd) party delivery service. The geographical distance between CP 100and NOC 300 may be a factor for choosing a specific type of VN 200. Forexample, a terrestrial network may be selected for a relatively shortdistance while a satellite link may be selected for the reception ofmultimedia content from a content provider of overseas. The amount ofdata and type of data may also be a factor for choosing the type of VN200. For example, if multimedia content are for a live-broadcasting, thecontent may be delivered by a high bandwidth network such as a satellitelink. However, if the content is not for live-broadcasting (e.g.,video-on-demand), the content may be delivered with slower terrestriallink. For some applications where time is not important (e.g., routineupdate to a stored on-demand video library), the multimedia content maybe delivered via third party carriers such as FedEx, UPS, etc.

Network Operation Center

NOC 300 provides a management center for IBN 10 in which multimediacontent received from CP 100 (which may be a customer of the IBN) isprocessed for delivery to EN 500 by (1) converting the content into adigital format (if necessary), (2) formatting the content into an IPformat (if necessary), (3) encoding the content for streaming (ifnecessary), and (4) formatting the content for satellite transmission.NOC 300 may comprise any computer, or group of interconnected computers,that performs these functions. If the received content is in an analogformat, e.g., a television broadcast, NOC 300 may convert the content toa digital format, e.g., MPEG. If the received content is not in an IPformat, NOC 300 converts it into IP format. NOC 300 encodes themultimedia content for streaming format where it is not already instreaming format. Encoding for streaming format is well known in theart. The multimedia content may also be compressed with the encoding.NOC 300 further converts the format of the content received from CP 100into a format suitable for transmission on satellite 400. For example,as described further below, NOC 300 may encapsulate the IP formattedcontent into a Digital Video Broadcasting (“DVB”) format for satellitetransmission. NOC 300 then delivers the content to EN 500 via satellite400.

In addition, NOC 300 may store the multimedia content collected from CP100 on the servers of NOC 300 if desired. NOC 300 also may monitor thereceived content for quality service.

Also, throughout the process, NOC 300 may diagnose any networkmalfunctions and gather network performance data for quality service.Other additional functions of NOC 300 may include, for example,providing the customer interface for managing accounts with CPs andLMSPs.

Additionally, NOC 300 may communicate with CP 100 to schedule forcontent acquisition and delivery. The received multimedia content fromCP 100 may be classified into several categories at NOC 300 (e.g., alive broadcasting, video-on-demand, etc.) for separate delivery options.Some of the content may be stored at a memory of NOC 300 for laterdelivery and some of the content may be delivered instantly. Additionaldetails of NOC 300 will be described in a later section.

Although FIG. 1 shows only one NOC 300, there may be multiple numbers ofNOCs distributed geographically covering wider area. For example, oneNOC may be located in Europe and another NOC may be placed in NorthAmerica covering the two areas. The two NOCs may be connected withcommunication links, such as a private or public ATM, thereby enablingflexible movement of the content and other data between the multipleNOCs.

Satellite

Satellite 400 provides a communication link between NOC 300 and EN 500through which streamed multimedia content may be delivered from NOC 300to EN 500. Satellite 400 may be adapted to receive the content on anuplink from the transmitter of NOC 300 and to transmit the receivedcontent on a downlink to EN 500. This may be referred to as a forwardchannel. Satellite 400 may also be adapted to receive information fromEN 500 on a second uplink and to transmit the received information on asecond downlink to NOC 300. This may be referred to as a reversechannel. It will be appreciated that the communication channel used maybe the same for the first and second uplinks and downlinks,respectively, and can be re-used. Although only one satellite is shownin FIG. 1 between NOC 300 and EN 500, multiple satellites may be usedmaking inter-satellite links to cover wider areas. Satellite 400 may bein a geostationary orbit, or other orbits may be used, and those ofordinary skill in the art will understand the additional communicationsoverhead needed to communicate with satellites in other thangeostationary orbit.

Edge Node

EN 500 provides a node for receiving multimedia content from NOC 300,and may be configured to receive multimedia content directly fromsatellite 400, thereby avoiding traffic delays caused by the internet.EN 500 may also be configured to accept multicast input from NOC 300.Although FIG. 1 shows only one edge node, it should be understood thatthe IBN of the present invention may comprise a plurality of edge nodes,where each EN 500 may be located at the “edge” of the internet backboneand as close as possible to end users. Each EN 500 may be capable ofdelivering received multimedia content to end users (e.g., subscribersto CP 100) through an LMSP. Each EN 500 may be co-located with an LMSPto avoid further delay caused by transmitting between EN 500 and theLMSP. An end user connected to an LMSP may access an EN 500 through hiscomputer to receive and to view the streamed multimedia content on hiscomputer screen.

The multimedia content downloaded from satellite 400 may be classifiedinto several categories at EN 500 depending on the types of data (e.g.,live broadcasting, video-on-demand, etc.) for separate delivery optionsto end users. For non-live content (e.g., video-on-demand), users mayaccess the content stored on the EN 500 nearest to them. For livecontent such as news and sporting events, the content may be passed onto end users without storing it in EN 500. However, some of the streamsfor the live broadcasting may also be stored at a memory of EN 500 forlater delivery. The multimedia servers of EN 500 are configured todeliver either live content, non-live content, or both simultaneously.The details of EN 500 will be described in a later section.

Back Channel

BC 600 provides a terrestrial communication link between NOC 300 and EN500. BC 600 may be used for “heartbeat” information between NOC 300 andEN 500 and for communicating control commands to remotely control EN500. Or, EN 500 may gather statistics on end users access to content andperiodically provide this information to NOC 300 via BC 600 to let NOC300 know that certain programs are still alive and operational. NOC 300may use this information for delivery scheduling. The internet, PublicSwitched Telephone Network (“PSTN”), or any other private or publicnetwork may be utilized for BC 600. BC 600 may be either a one-waycommunication link or, a two-way communication link for more interactiveoperation of IBN 10.

End Users

An end user, connected to an LMSP, may access EN 500 to receive thestreaming multimedia content with, for example, his personal computer orset-top box. The LMSP may provide the end user with a high speedinternet connection such as DSL, ISDN, wireless or cable modem. The enduser may run a streaming multimedia application (e.g., Real NetworkPlayer, Microsoft Windows Media, and Apple QuickTime etc.) to view thestreaming multimedia data. Upon connection to EN 500, the end user maybe provided with streaming multimedia content.

DETAILED DISCUSSION OF THE FIGURES

The operation of IBN 10 will now be described with reference to FIGS. 1and 2 along with the flow chart of FIG. 3.

FIG. 2 illustrates the end to end connection of IBN 20 including LMSPsand end users. The same numerals are used as in FIG. 1 for CP 100, VN200, NOC 300, satellite 400, EN 500, with the exceptions that three ENsare shown in FIG. 2 (EN 500A, EN 500B, EN 500C). The users A, B, C areeach connected to the internet 30 via one of the LMSPs, for example, DSLprovider 35, cable modem provider 37, wireless internet provider 39,respectively.

CP 100, trying to deliver multimedia content to its subscribers, e.g.,users A, B, or C, through the internet, may request that a contentdelivery service be established with NOC 300. CP 100 may use any kind ofcommunication link to contact NOC 300 to place the service request. Forexample, a person in CP 100 may visit the web site of IBN 20 which isdesigned to receive the service request, or may place a call to themanager of NOC 300.

In response to the content delivery service request from CP 100, NOC 300schedules the reception of multimedia content from CP 100 and deliveryof the received multimedia content to ENs 500A, 500B, 500C.

FIG. 3 is a flow chart illustrating an exemplary process by which IBN 20of FIG. 2 collects multimedia content from CP 100 upon receiving arequest from CP 100 and delivers the received multimedia data to the endusers A, B, C.

At step 710 of FIG. 3, NOC 300 receives multimedia content from CP 100.Referring to FIG. 2, NOC 300 may receive the multimedia content from CP100 via satellite 200. The multimedia content received from CP 100 mayor may not be in an IP format. Where the content is not received in anIP format, NOC 300 may convert the content to an IP format.

At step 715, after receiving the data, NOC 300 encodes and compresses itusing a streaming media standard such as, for example, MPEG, RealPlayer,or Windows Media Player format. For example, using the MPEG-2, two hourvideo data may be compressed into a few Gigabytes. When the multimediacontent is not live, media files so encoded may be placed in a package(e.g., zip file) for transmission to EN 500. Similar packages may beused to transmit commands from NOC 300 to EN 500. A detailed explanationregarding the packages are described below.

At step 720, NOC 300 converts the format of the encoded content orpackages into a format suitable for a common communication link betweenNOC 300 and one or more of the ENs, such as for example, Satellite 400.For example, an IP gateway of NOC 300 performs the multi-protocolencapsulation of UDP and IP packets into MPEG-2 packets for delivery ofcontent using a digital video broadcasting (“DVB”) format. The IPgateway may also put the program ID numbers (“PIDs”) to indicatespecific destinations of the transmitted data streams. By using the PIDmethod, multiple content files may be transmitted simultaneously suchthat their packets are intermixed. Each packet has a PID number so thatreceiving ENs can determine what packets belong to what file. In thecurrent example, the destinations would be ENs 500A, 500B, 500C.

At step 725, NOC 300 modulates the DVB packets. A modulator of NOC 300modulates the DVB packets with one of the digital frequency modulationtechniques for transmission via a satellite network. For example, theDVB packets may be modulated using the quadrature phase shift keying(“QPSK”) modulation technology. The modulator may also encode the DVBpackets for an error correction using, for example, both convolutionalViterbi and Reed Soloman block coding.

At step 730, NOC 300 uploads the DVB packets to satellite 400. Beforethe transmission, the transmitter may first convert the frequency of themodulated DVB packets to a radio frequency suitable for a satellitetransmission.

At step 735, satellite 400 downloads the DVB packets to land-based(although an EN could also be sea, air or space based) ENs 500A, 500B,500C of IBN 20. Satellite 400 of IBN 20 re-transmits the DVB packetsdownloading the DVB packets to ENs 500A, 500B, 500C. In the currentexample, ENs 500A, 500B, 500C are designated ENs and only these nodesmay handle the DVB packets by interpreting the PID contained within theDVB packets. For example, the three ENs are designated as destinationnodes by the IP gateway of NOC 300 at step 720.

At step 740, each of ENs 500A, 500B, 500C demodulates the DVB packetsreceived from satellite 400. Each of the demodulators of ENs 500A, 500B,500C demodulates the downloaded DVB packets. The demodulators may alsodown convert the radio frequency signal to an intermediate frequency(“IF”) signal prior to the demodulation.

At step 745, each of ENs 500A, 500B, 500C extracts IP packets from thereceived DVB packets.

At step 750, each of ENs 500A, 500B, 500C decodes and decompresses theIP packets. If the IP packets are formatted with a package (e.g., anon-live content), the IP packets are extracted first before thedecoding/decompressing.

At step 755, each of ENs 500A, 500B, 500C determines whether the IPpackets are non-live content or live content. The process proceeds withstep 760 if the IP packets are non-live content. If the IP packets arelive content, the process proceeds with step 770.

At step 760, in the case of non-live content, each of ENs 500A, 500B,500C stores the IP packets in a storage device. The multimedia contentis now ready for delivery to end users A, B, C by the media servers ofENs 500A, 500B, 500C.

At step 765, media servers of ENs 500A, 500B, 500C stream the multimediacontent to the end users A, B, C, respectively, through respective LMSPs35, 37, 39. For example, users A, B, C each connected to DSL provider,cable company, and wireless internet provider receive the streamsthrough DSL connection 35, cable modem 37 and wireless modem 39,respectively.

At step 770, in the case of live content, the media stream received viathe IP packets is forwarded to the media servers of ENs 500A, 500B, 500Cfor immediate distribution, and the IP content is subsequently streamedto interested end users at step 765. In some cases, the live content mayalso be stored by ENs 500A, 500B, 500C so that the content may be madeavailable to end users at a later time as non-live content.

Users A, B, C may request the multimedia service from CP 100 while, forexample, visiting the web site of CP 100. The web site of CP 100 may beconfigured to receive the requests by showing available programs (e.g.,video-on-demand) or time schedules for live broadcasting (e.g., sportsor news, etc.). Users A, B, C may click on one of the options to receivethe multimedia stream service from CP 100 by providing appropriateinformation (e.g., billing information or ID-password, etc). The website of CP 100 may also be configured to determine automatically whichone of ENs 500A, 500B, 500C is best able to serve the users uponreceiving the service requests using, for example, an InternetRedirection Engine (“IRE”). If an EN does not have multimedia contentthat a user wants, the web site may direct the user to another nearestEN that has the content. Alternatively, each of the users A, B, C mayvisit the web site of their respective LMSPs for a request.

Beside the IBN that is in use, there may be an additional implementationof part of the IBN in which one or more of the components of the IBN areduplicated or simulated. For example, the additional implementation mayinclude a duplicate NOC, a simulated satellite, a duplicate edge node,and a duplicate end user. Duplicate components, such as, for example, aduplicate NOC, edge node, or end user, have the same functionality andhardware and software configuration as the components they correspond toin the IBN in use. Simulated components, such as, for example, asimulated satellite, are simulated to duplicate the functionality of thecomponents they correspond to in the IBN in use.

This additional implementation of part of the IBN may be used foroff-line testing of the IBN in use. Since the additional implementationduplicates the functionality and operation of the IBN in use, theadditional implementation may be used to test changes one desires tomake in the IBN in use without affecting the IBN in use. By using theadditional implementation, the network manager can determine, forexample, how long a certain upgrade to an element of IBN in use (e.g.,NOC 300, EN 500, etc.) would take and in what sequence modificationsneed to be performed. The effects of mixing and matching newapplications may also be checked for problems before they are installedon the IBN in use. Thus the additional implementation may be used as aduplicate system for testing to help maintain the reliability of the IBNin use and minimizes service disruptions in the IBN in use.

Network Operation Center

Referring back to FIG. 1, it may be seen that NOC 300 comprises a router302 for routing received multimedia content, a broadcast manager 304 forcontrolling the general operation and communicating with contentproviders to scheduling delivery of content from the content provider tothe NOC, as described above, content storage 306 for storing receivedmultimedia content from content providers, IP gateway 308 for convertingthe format of received content, servers 310 for processing the receivedcontent and uplink transmitter 312 for transmitting multimedia streamsto satellite 400.

FIG. 4 is a block diagram showing exemplary functional blocks of NOC300. Here it is assumed that virtual network 200 includes satellites toreceive multimedia content from CP 100.

Receiver 332 of NOC 300 acquires multimedia content from satellite dish(or dishes) 330 which may receive content from CP 100. Receiver 332,upon receiving the signals from satellite dish 330, amplifies the signaland downconverts the signal if necessary from radio frequency (“RF”) tointermediate frequencies (“IF”) for processing within NOC 300. Receiver332 demodulates and decodes the signal to retrieve encoded analog videoand audio when necessary. Receiver 332 next provides an output to thevideo/audio monitoring and processing equipment 334.

Monitor 334 of NOC 300 allows an operator to monitor the incomingsignals, and to prepare the signals for input to the streamingvideo/audio encoder equipment 336. The output of satellite receiver 332is applied to the amplifier (not shown) of monitor 334 providing themeans for monitoring the incoming signals. Video and audio outputs maybe displayed on a color video monitor and a speaker, respectively.Additionally, waveform monitors and vectorscopes of the video/audiomonitoring/conditioning equipment may provide alternate means forverifying video signal quality. The output from receiver 332 alsocorrects the levels of the incoming signals, and provides video andaudio outputs to streaming encoder 336.

Streaming encoder 336 of NOC 300 accepts content received from CP 100and formats or compresses it, or both, into a streaming media fileformat such as, for example, Windows Media or RealMedia. Where thecontent received by encoder 336 is not in an IP format, then encoder 336may also modify the content into an IP format. Encoder 336 then forwardsthe formatted and/or compressed data to origin server 338. When thecontent is not live, one or more of the formatted and/or encoded mediafiles may be placed in a package for transmission to EN 500.

Origin server 338 of NOC 300 receives the packages or media files andrelays them to uplink server 342 via router/switch 302. For live contentdistribution, Streaming Media Server Software, such as, for example,Real Server software, may be installed on origin server 338 to providethe means for accepting content from streaming encoder 336. TheStreaming Media Server Software, which may have several other functions,may be configured as a push source in origin server 338 to simply pushcontent that it receives from streaming encoder 336.

Router/switch 302 of NOC 300 may be a virtual local area network(“VLAN”) to interconnect the encoders and servers of NOC 300. MultipleVLANs may exist allowing for the routing of traffic between the VLANs.Router/switch 302 may also provide the ability to interface to externalnetworks such as private or public ATM network.

Uplink server 342 of NOC 300 receives the packages or media files fromorigin server 338 and re-transmits them to IP gateway 308. StreamingMedia Server Software, such as, for example, Real Server, may also beinstalled in uplink server 342 and configured as a push splittertransmitting the packages or media files without a request from endusers. This means that uplink server 342 may provide multimedia contentto multiple destinations. The Streaming Media Server Software may alsobe configured for a scalable multicast permitting the transmission to anunlimited number of ENs with a one-way transmission, e.g., nobackchannel. The Streaming Media Server Software may also be configuredfor Session Announcement Protocol (“SAP”), which announces the presenceof these multicast transmissions to the targeted ENs. For non-livecontent distribution, server 342 may instead run FTP (File TransferProtocol) or TFTP (Trivial File Transfer Protocol) server software.

It should be noted that the functionality of streaming encoder 336,origin server 338, and uplink server 342 may reside in one or more ofthe servers 310 of FIG. 1.

Returning to FIG. 4, IP gateway 308 of NOC 300 is a re-encapsulator.Upon receiving the packages or media files (e.g., IP packets), IPgateway 308 may encapsulate the IP packets to packets of a formatdesigned for transmission over satellite 400, such as, for example, thedigital video broadcasting (DVB) format. The DVB is an establisheddigital video standard that permits the transmission of video, audio,and other data over a common communications link such as a satellitenetwork. The DVB standard also permits the use of Program ID numbers(PIDs). One of the functions of the PIDs is to allow for the targetingof specific data transmissions to specific receive locations enabling amulticast input for distribution to multiple predetermined ENs.

Modulator 346 of NOC 300 accepts the encapsulated data (e.g., IP packetswhich have been encapsulated in DVB packets), encodes the data for errorcorrection, and modulates the packages or media files using, forexample, QPSK modulation for transmission via satellite 400. Modulator346 may use both convolutional Viterbi and Reed Soloman block coding toaffect the encoding for error correction.

Transmitter 348 of NOC 300 converts the frequency of the output ofmodulator 346 to radio frequency (e.g., 14–14.5 GHz) suitable fortransmission via satellite 400. For example, the radio frequencyequipment amplifies the upconverted signal in the high-power amplifier,then amplifies the signal again to transmit the signal to the satellitethrough the uplink satellite antenna 350. Transmitter 348 transmits themodulated packets to satellite 400 via a satellite transmission dish(not pictured).

NOC 300 may also include equipment that duplicates the functionality ofan edge node and one or more end users. Such equipment may be used tosimulate the downlink operation of an edge node and end user of IBN 20without interfering with the operation of the edge node and end userbeing simulated.

The equipment in NOC 300 providing the duplicate functionality mayinclude duplicate equipment. In other words, to duplicate thefunctionality of an edge node and one or more end users, NOC 300 mayinclude all the equipment necessary to make up an edge node and one ormore end users with the equipment being configured in the same manner asthe edge node and one or more end users of IBN 20 whose functionality isbeing duplicated. Alternatively, the equipment in NOC 300 providing theduplicate functionality may include equipment that simulates theoperation of an edge node and end users, such as a computer andsimulation software.

With the equipment that duplicates the functionality of an edge node andend users, as described above, NOC 300 simulates the downlink operationwithout interfering with the systems in use, such as EN 500 and endusers A, B, C.

Also, the functionality of NOC 300 may be incorporated into a portablerack which can be transported easily and does not need to be reassembledat its destination. The mobilized NOC may be equipped with thefunctionality of the NOC previously described above, including, forexample, the encoding function to encode content to streaming mediaformats, such as, for example, Real and Windows media, and IPmulticasting function to transmit the encoded content to multiple ENs.The operator may carry the mobilized NOC to a place where non-mobile NOCequipment cannot reach (e.g., remote mountain, remote island, etc.) fora live-broadcasting of a special event through the internet.

Edge Node

Referring back to FIG. 1, exemplary EN 500 comprises a ground antenna502 for receiving data from satellite 400 and at least one rack 504which includes data processing devices. Antenna 502 may be located, forexample, on the roof of a LMSP premises and rack 504 may be placed, forexample, inside the building. While antenna 502 and rack 504 may beconnected through a coaxial cable (e.g., plenum rated RG-11 RF cable),fiber optic cable may also be used where the cable length exceeds RG-11specification.

Antenna 502 may comprise a satellite dish with the size of the dishdepending on factors including, for example, where the installation isto take place geographically. In one embodiment, a VSAT (“very smallaperture terminal”) with 1.2 meter (four feet) or 1.8 meter (six feet)diameter may be used. A special design method (e.g., non-penetratingroof mounts) may be used for the satellite dish to withstand strongoutside winds. For example, the satellite dish may need to resist windsof 100 MPH and exert less than 20 pound per square foot on the roof. Theantenna may be a “receive-only” in this embodiment. Alternatively, inanother embodiment, the antenna may transmit as well.

FIG. 5 is a block diagram of rack 504 of FIG. 1 in which examples offunctional elements are illustrated. Rack 504 may comprise a server 510capable of providing live multimedia content, non-live multimediacontent, or both, shared storage 512, receiving router 514, receiver516, RF gain amplifier 518, demodulator 520, gateway 522, and decoder524, switch 526, router 528, firewall/VPN (Virtual Private Network) 530and input/output unit 532.

Upon receiving a transmission from NOC 300 through receiving router 514,receiver 516 down converts the frequency for further processing. Gainamplifier 518 may then amplify the signal. Demodulator 520 demodulatesthe signal. Gateway 522 converts the format of the received data from aformat designed for satellite transmission to an IP format. For example,where the data is received in a DVB format, then gateway 522 extracts IPpackets from the DVB packets. Switch 526 and router 528 are for routingcontent streams to a LMSP. A human operator may input a command and viewthe status of the operation of EN 500 through I/O unit 532. Rack 504 mayfurther comprise interfaces 534 and 536 to interface with antenna 502and a LMSP, respectively.

FIG. 6 depicts an exemplary EN rack that may comprise four dual-733 MHzIntel Pentium III processor servers (e.g., the Power Edge 2450 modelserver from Dell Computer Corp.), an RF gain amplifier, two satelliterouters (e.g., the Enterprise1 from Harmonic Data Systems), a networkswitch (e.g., Model Catalyst 2924 from CISCO Systems), two remote powercontrollers (e.g., Model AP9211 from APC), a firewall device (e.g.,model NetScreen-10 from NetScreen Technologies), multiportkeyboard/display controller (e.g., model KVM-8 from APC), andkeyboard/mouse/display unit. Two of the servers are configured fornon-live content and the other two servers are configured for alive-broadcasting, and each has a 72 Gigabit disk array attached (e.g.,the Power Vault 2005 model from Dell Computer Corp.). Alternatively,each server may be configured to send simultaneously both live andnon-live content. The cabinet dimensions may be, for example,19″×36″×84″. However, any other size or number of racks may be used toaccommodate the rapid growth of high speed internet users. For example,two of the racks may be used side-by-side for system expansion. Fornetwork connectivity, a total of nine 100 Mbps fast Ethernet connectionsmay be used to the routers of the LMSP. Eight of the routers may be usedto stream video to LMSPs, and the ninth may be used for the edge serverswitch. Alternatively, a single Gigabit Ethernet connection may be usedto the LMSP routers.

FIG. 7 shows a structure of an exemplary EN 500 as an embodiment of thepresent invention. EN 500 contains two virtual local area networks(VLANS) 550 and 560. VLAN 550 may be called a “private” VLAN becausethere is no direct link from a conventional network to this VLAN fromoutside EN 500. VLAN 560 may be called a “public” VLAN because, asexplained below, there may be a direct link from a conventional networkto VLAN 560 from outside EN 500. Receiving router 514 and controller 540are connected to VLAN 550, while router 528 and switch 526 (e.g., anoptional load balancer) are connected to VLAN 560. Multimedia content(e.g., DVB packets) received from satellite 400 arrives at controller540 via “private” VLAN 550 while multimedia content (e.g., DVB packets)received from BC 600 arrives at controller 540 via “public” VLAN 560.Media servers 510 are connected to both VLANS by, for example, twonetwork cards/interfaces, but do not provide a thoroughfare betweenthem. As is known in the art, through the use of VLANs, a node'sbroadcast domain assignment need not be determined by its physicallocation. VLANs may be established, for example, through the use ofappropriate switches such as, for example, those of the 3Com SuperStackseries, the Plaintree WaveSwitch series, and the Cisco Catalyst series.

Router 528 provides connectivity between VLAN 560 and LMSP 550 vianetwork link 552. EN 500 of the present invention may also includefirewall/VPN 530 (virtual private network) to provide connection betweenVLANs 550 and 560 without compromising the security of VLAN 550. Aconnection between the two VLANs may be made using a secure VPN therebyenabling the private side of EN 500 to be accessed from outside EN 500for various administrative purposes.

A discrete controller 540 is used for the operation of EN 500 as shownin FIG. 7. Alternatively, the functionality ascribed to the controller540 may be incorporated into other components of EN 500, such as, forexample, one of the servers 510.

Multimedia content sent from NOC 300 to EN 500 via satellite 400 arrivesat dish 502 in the form of IP format packets encapsulated within packetsof a format designed for satellite transmission, such as, for example, aDVB format. Flowing through receiving router 514, receiver 516, gainamplifier 518, demodulator 520, and gateway 522, the packets are sent tocontroller 540 via VLAN 550. Alternatively, packets sent from NOC 300 toEN 500 via BC 600 travel through router 528 of VLAN 560, firewall/VPN530, and then arrives at controller 540.

Each of the hardware components of EN 500 could be implemented usingcustom-built or commercially-available devices. For example, receivingrouter 514 may be implemented using a Harmonic Enterprise 1. Switch 526(e.g., load balancer) may be implemented, for example, using aFoundryNetwork ServerIron XL L4 switch. Router 528 may be implemented,for example, using a Cisco 12012, and firewall/VPN 530 may beimplemented using, for example, a NetScreen Technologies' NetScreen-100.Shared storage 512 may be implemented as a JBOD (just bunch of disks)such as, for example, the Unisys OSR700 JBOD. Shared storage device 512could also be implemented as a redundant array of independent disks(RAID).

Each of servers 510 and controller 540 may be implemented using astandard general purpose computer or workstation, such as, for example,a PowerEdge model server from Dell Computer Corp. running Windows 2000System Software from Microsoft Corp. or a Power Macintosh G4 modelserver running OS X Server Software, both from Apple Computer. Such ageneral purpose computer may comprise one or more processors operativelyconnected to memory units (such as RAM, ROM, or mass storage) containingprogram code and data, whereby the processor or processors may executethe program code and modify or access the data. Each of servers 510 mayhave two network interface cards and be running media server softwaresuch as, for example, Real System Server Software from Real Networks orWindows Media Server Software from Microsoft Corp. Controller 540 wouldbe running data manager software crafted in accordance with the abovedisclosure using a computer language known in the art such as C, C++,Objective-C, or Java.

The details of multimedia content processing by EN 500 will now bedescribed. The processing may be divided into two sections for non-livecontent (e.g., a package) and live content (e.g., media files).

Controller 540 runs software called a “data manager”. The data managerpositions non-live multimedia content on EN 500 and executes commandsreceived from NOC 300. The data manager also allows for controlling theoperation of EN 500 remotely by sending and receiving commandinformation from NOC 300. The data manager is responsible for storingand processing packages received at controller 540 of EN 500. The datamanager may also perform updates of software on EN 500, uploads log toNOC 300 reporting the control status to NOC 300, and updates the EN'sregistry entries.

Content received by EN 500 may be stored on one or more EN servers 510or, on a shared storage 512 connected to controller 540 by a connection544. Connection 544 may be made using fiber channel, IEEE 1394,Ethernet, or other connections that are known in the art. Shared storage512 is storage shared by multiple servers 510 of EN 500. Alternatively,packages may be stored on a dedicated storage device connected tocontroller 540. The data manager may be run, for example, as a Javaapplication or applet, a Windows NT service, a background application(e.g., a daemon), or as a command-line application.

FIG. 8 is a flow chart illustrating an exemplary process by which thedata manager of controller 540 of EN 500 operates upon receiving apackage of multimedia content.

Although a discrete controller 540 is used in this example, it is notedthat the behavior ascribed to controller 540 may be incorporated intoother components of EN 500, such as one of its media servers.

According to at least one embodiment of the invention, the package isaddressed to controller 540 of EN 500 using IP multicast and may bereceived at the edge node via either satellite 400 or BC 600 dependingon the speed of transmission desired. For example, if high speedtransmission of the package is desired, the package may be transmittedand received over satellite 400. However, if a slower transmission speedis acceptable, the package may be transmitted and received over BC 600.As alluded to above, the package sent to controller 540 via satellite400 arrives at satellite dish 502 in the form of UDP packetsencapsulated within IP packets which are again encapsulated within DVBpackets. After appropriate extraction, the package containing IP packetsare sent to controller 540 via VLAN 550. Alternatively, if the packageis sent to EN 500 via BC 600, the packets which make up the packagetravel through router 528, over VLAN 560, through firewall/VPN gateway530, and then over VLAN 550 to controller 540.

Referring to FIG. 8A, a package is received from NOC 300 (step 810). Atstep 820, it is determined if the expected package was successfullyreceived at controller 540.

If the package was not successfully received, the data manager may sendan error message to NOC 300. Error informing messages may be sent via BC600 using methods known in the art such as, for example, Java MessageService (JMS). Alternatively, in another embodiment no error message issent. If the package was not successfully received, then after an errormessage, if any, is sent, the data manager may cease processing of thepackage.

If the package was successfully received, a success message may be sentto NOC 300. Alternatively, in another embodiment, no success message issent.

Returning to FIG. 8A, regardless of whether or not a success message issent, if the package has been successfully received at controller 540,it is stored at shared storage 512 (step 830). Then the data managerbegins processing of the package by examining it to estimate how muchspace is required to decompress the package (step 840). Next, it isdetermined if there is enough space available on EN 500 to decompressthe package (step 850). If there is enough space, then processingcontinues (Connector A) with step 900 and FIG. 8B.

Returning to FIG. 8A, if there is not enough space, the data managerconsults the controller 540's database in order to determine whether anypreviously received files have expired or are marked for forced deletionand may be deleted from edge node storage (step 860). Depending on thecontroller's database, checking for expired files may be done bysearching the parameter database for files whose expired field containsBoolean “true”, or for files whose expiration data field contains a datewhich, in light of the system or network clock, indicates that the filehas expired. To check for files marked for forced deletion, the datamanager consults the controller's database to search for the occurrenceof Boolean “true” in the “forced delete” field of database entriescorresponding to files located on the node. The data manager may bedesigned to periodically check for and delete files that have expired orare marked for forced deletion in addition to performing this operationwhen a new package has arrived.

If there are no previously received files that are expired or marked forforced deletion, then there remains too little space to decompress thepackage and processing flows to step 890 where the data manager sends anerror message to NOC 300 over BC 600 indicating this. The data managermay then cease processing the package.

If there are previously received files that are expired or marked forforced deletion, then the data manager deletes one or more of thesefiles (step 870). Any scheme desired may be used to determine whichexpired files or files marked for forced deletion, or both, should bedeleted. For example, the data manager may simply delete all files thatare expired or marked for forced deletion.

The data manager may accomplish the deletion of a file in any number ofways. For example, a file may be deleted by both removing it from itsstorage space using the delete command of the operating system and byremoving the file's entry in the database. Alternatively, a file's entryis not removed from the parameter database. Instead, the parameterdatabase includes a “deleted” field for each file, and the data managerplaces a Boolean “true” in this field after deleting the correspondingfile. Furthermore, rather than using the standard delete command of theoperating system, a special delete command may be performed whichprevents “un-deletion” of the file. This may be achieved by zeroing allstorage positions that were occupied by the file and marking thesestorage positions as free. If, for any reason, an expired file cannot bedeleted because, for example, the operating system indicates that thefile is in use, the data manager accesses the database and places aBoolean “true” in the “forced delete field” corresponding to the file.

As noted above, EN 500 may maintain in its database information for eachfile concerning the package from which it came. When a file originatedin a particular package is deleted, all of the files originated fromthat package are also deleted. The rationale employed in this concept ofthe invention is that a portion of a package should not be left on anEN. When only certain files of a particular package are capable of beingdeleted, the data manager will delete the files that are capable ofbeing deleted and for the rest set their respective “forced delete”flags to Boolean true. Alternatively, certain files originated from aparticular package may be allowed to remain while others are deleted.

Returning to FIG. 8A, after one or more expired files or files markedfor deletion are deleted in step 870, another check is made to determineif there is enough space available on EN 500 to decompress the package(step 880). If sufficient space still does not exist for decompressingthe package, the data manager may send an error message to NOC 300 overBC 600 indicating this (step 890) and then may cease processing of thepackage. If the data manager successfully frees up enough space todecompress the package, the data manager continues processing of thereceived package (Connector A) and flow proceeds to step 900 and FIG.8B.

FIG. 9 is a flow chart presenting an alternative embodiment of thepresent invention in which only as few files as necessary are deleted inorder to free space where initially there was not enough space todecompress the package. In the flow chart of FIG. 9, steps 810 through860 and step 890 may be performed in the same manner as the likenumbered steps of FIG. 8A, described above. Referring to FIG. 9, apackage is received from NOC 300 (step 810) and a check is made todetermine if the package was received successfully (step 820). If thepackage was not successfully received, the data manager may or may not,as desired, send an error message to NOC 300 and then may ceaseprocessing of the package. If the package was successfully received, asuccess message may or may not, as desired, be sent to NOC 300 and thenprocessing continues with step 830 where the successfully receivedpackage is stored. A determination is made as to how much space isneeded to decompress the package (step 840) and if there is enough spacethen processing continues (Connector A) with step 900 and FIG. 8B.Returning to FIG. 9, if there is not enough space, then a check is madeto determine if there are any previously received files that haveexpired or are marked for forced deletion (step 860). If there are nosuch files, then an error message is sent to NOC 300 over BC 600 (step890) and processing of the package may cease.

If there are previously received files that are expired or marked forforced deletion, then the data manager may delete as few files asnecessary to free up enough storage space to decompress the receivedpackage. To do that, the data manager may first delete all files markedfor forced deletion (875) and then check to see if enough free spaceexists to decompress the package (876). If enough space exists, thenprocessing continues (Connector A) with step 900 and FIG. 8B. Returningto FIG. 9, if not enough space exists after deleting all files markedfor forced deletion, then the data manager may check if there are anypreviously received files that are expired (step 877). If there areexpired files, then one or more expired files may be deleted (step 878)and processing flows back to step 876. If no expired files exist orthere are no expired files remaining, then processing flows to step 890where an error message is sent to NOC 300 over BC 600 and processing ofthe package may cease.

When deleting one or more expired files, as in, for example, step 878,different schemes may be employed to decide which files will be deletedbefore others. For example, the data manager may be programmed to chooseto first delete files with the oldest expiration dates or files whosedate of last use, as indicated by the operating system or an additionalmonitoring program, was the oldest.

Whether processing begins with the steps of the embodiment shown in FIG.8A or with the steps of the embodiment shown in FIG. 9, if there isenough space to decompress the received package, either initially orafter deletion of files, then processing continues with the steps ofFIG. 8B where the data manager may begin decompression of the receivedpackage. Among the content of the package may be a security certificate,a package information listing, and, depending on the package type,content files or command-related files, or both. The data manager neednot decompress the entire package at once and instead may extractelements from it the package one by one.

Referring to FIG. 8B, at step 900, the first item the data managerextracts from a package may be the security certificate. The datamanager parses the security certificate to verify that the package wasindeed sent by NOC 300 (step 910). Such security certificatefunctionality may be implemented by procedures known in the art such as,for example, by use of the Pretty Good Privacy (PGP) encryptionalgorithm and associated protocols. If processing of the securitycertificate determines that the package was not sent by NOC 300,controller 540 may send a message advising NOC 300 of this fact over BC600 (step 920) and may stop processing of the package. The package maythen be deleted, or in other embodiments it may remain until explicitlydeleted by a system administrator to allow for inspection of theof-questionable-origin package.

If the origin of the package is successfully verified, flow proceeds tostep 930 where the data manager extracts from the package the packageinformation listing. This file, which may be in XML format, may containinformation, such as, for example, the package type (e.g., command orcontent file), identification codes of EN 500 who is one of the intendedrecipients of the package, the package's identification code, and thepackage's creation date. If the package is a content containing package,it may additionally include in the package information listing anindication of the content files contained within the package. Thislisting may also note for each file the file's expiration date, theserver type or specific server it was meant for, and the start date forthe file.

If the package is a command-containing package, then the packageinformation file may contain one or more commands and, depending on thetype of command, additional information needed for executing the commandor commands such as, for example, a listing of files contained in thepackage which are necessary for performing an update. In otherembodiments, the information listing may not contain actual commands andinstead may include a listing of files within the package that containthe commands and any additional information relevant to executing thecommands.

Returning to FIG. 8B, upon examining the information listing, the datamanager may determine if it is an intended recipient of the file (step940). If the data manager determines that it is an intended recipient,then processing continues (Connector B) with step 950 and FIG. 8C.Otherwise, processing of the package stops.

Referring to FIG. 8C, if the data manager has determined that it is anintended recipient of the package, controller 540 further examines theinformation listing to determine whether the package is a commandpackage or a content-file package (step 950).

If the data manager determines that the package is a content filepackage, controller 540 would extract the content from the package (step960) and transmit it to either a directory on the shared disk system or,upon one or more of the servers when a shared disk system is not adopted(step 970). Where content files are to be placed on the servers ratherthan on a shared disk system, the package information listing mayspecifically stipulate which particular servers of the edge node shouldreceive each file contained within the package. If there is such astipulation, then the data manger places the received files on theservers in accordance with the stipulation. However, where the contentfiles are to be placed on the servers rather than on a shared disksystem, and no placement stipulation is received from NOC 300, then thedata manager has to make its own determination as to which serversshould receive which files.

In order to make this determination, there are a number of factors thatthe data manager may be programmed to take into consideration. Onefactor is the server type that a particular file is meant for. Forexample, the data manager may be programmed to only place Real Mediafiles onto Real Media severs. Additionally, when there exist more thanone server of a particular type, the data manager may be programmed todecide how many of these servers should receive a particular file. Forexample, in an edge node containing three Real Media severs but nocommon storage, it must be decided which of these severs should receivea file of Real Media format.

Another factor the data manager may be programmed to consider isavailable storage space on each of the appropriate severs. For example,only a certain number of the Real Media servers may have enough storagespace to receive a particular Real Media content file. Further, the datamanager may be programmed to weigh competing factors. For example,choosing to place a particular content file on a greater number ofservers allows a greater number of users to view a particular filesimultaneously. On the other hand, this leads to being able to storefewer unique files on a particular node; from the standpoint of thetotal node storage, in the case where a copy of a particular contentfile is stored on three servers of the node one file takes up as muchtotal room as three different files.

However, by employing shared storage device 512, the data manager wouldno longer need to make a decision about which servers of a particulartype in an edge node should receive a particular content file. Instead,a single copy could exist on the shared storage device and be accessibleby all servers that supported that file type. Thus the benefit of havingthe file stored at each server of a particular type would be realizedwithout the cost of increased storage use due to there being multiplecopies of particular content files.

Returning to FIG. 8C, after the content files have been extracted andsent to their target locations (e.g., a directory on the shared disksystem 512 or one or more of the servers 510 if a shared disk system isnot adopted), the data manager records in the controller's database thename or identifier of each received content file along with anappropriate entry for the expiration date, expired, start date,server-type, file location, and forced delete fields (step 980). Thedata manager then deletes the package file (step 990) and sends amessage to NOC 300, perhaps over BC 600, informing it that the contentfiles contained in the received package have been placed on the node'sstorage (step 1000).

As noted above, the package information listing may include informationthat indicates a start date and an expiration date for a content file.The controller may be Further, the data manager may be programmed toweigh competing factors. For example, choosing to place a particularcontent file on a greater number of servers allows a greater number ofusers to view a particular file simultaneously. On the other hand, thisleads to being able to store fewer unique files on a particular node;from the standpoint of the total node storage, in the case where a copyof a particular content file is stored on three servers of the node onefile takes up as much total room as three different files.

However, by employing shared storage device 512, the data manager wouldno longer need to make a decision about which servers of a particulartype in an edge node should receive a particular content file. Instead,a single copy could exist on the shared storage device and be accessibleby all servers that supported that file type. Thus the benefit of havingthe file stored at each server of a particular type would be realizedwithout the cost of increased storage use due to there being multiplecopies of particular content files.

Returning to FIG. 8C, after the content files have been extracted andsent to their target locations (e.g., a directory on the shared disksystem 512 or one or more of the servers 510 if a shared disk system isnot adopted), the data manager records in the controller's database thename or identifier of each received content file along with anappropriate entry for the expiration date, expired, start date,server-type, file location, and forced delete fields (step 980). Thedata manager then deletes the package file (step 990) and sends amessage to NOC 300, perhaps over BC 600, informing it that the contentfiles contained in the received package have been placed on the node'sstorage (step 1000).

As noted above, the package information listing may include informationthat indicates a start date and an expiration date for a content file.The controller may be programmed to not make a particular content fileavailable to users before the start date or after the expiration date.For example, the controller may control the read privileges of a fileusing commands built into the operating system running on the computersof the edge node so that the servers could not read it before the file'sstart date or after its expiration date.

Returning to FIG. 8C, if, at step 950, the data manager determines thatthe package is a command package rather than a content file package, thedata manager executes the command or commands contained in the package(step 1010). Described below are examples of the commands which may bereceived in the package including, without limitation, the followingcommands: Upload Logs, Software Update, Delete Content, Request FileStatus, Request Content, Update Settings, and Request Settings.

As mentioned above, one example of a command that may be sent to EN 500via a package is the “UploadLogs” command. In response the data manageruploads to NOC 300 all or part of the logs contained in the database ofEN500. Such uploading may be performed as a background process or via athread as is known in the art. The transfer to NOC 300 may be done, forexample, over BC 600 using FTP protocol. During the transfer process,the background process or thread will monitor for the success of theoperation. If the transfer executes completely and successfully, thecontroller 546 will send a “LogTransferSuccessful” message to NOC 300.If the transfer is not successful, the controller will send a“LogTransferUnsuccessful” message to NOC 300. In other embodiments, NOC300 may send a “LogTransferSuccessful” or “LogTransferUnsuccessful”message, as appropriate, to the controller in lieu of or in addition tothe above described transmission of a message from the controller to NOC300. Additionally, while the controller is uploading log information toNOC 300 it sends a “heartbeat” message to NOC 300 every n seconds toindicate to NOC 300 that the connection between NOC 300 and EN 500 isstill active. Such messages may be sent using methods known in the artsuch as Java Message Service (JMS). The data manager software may recordin the database of EN 500 the time and date of each attemptedtransmission of the log, along with an indication of whether the attemptwas successful or not. Alternatively, the data manager software may onlyrecord the time and date of successful transmissions of the log.

Another example of a command is the “SoftwareUpdate” command. Inresponse to this command the data manager acts to update itself or thesoftware running on other components of the edge node such as itsservers. When the package information listing specifies this command italso includes additional information necessary for carrying out thecommand.

Under certain circumstances, a generalized updater program will exist onEN 500, perhaps being stored at shared storage 512, in a hard drive, orother form of storage contained within controller 540. A packageinformation listing specifying the SoftwareUpdate command wouldadditionally specify, as additional information, the arguments to beused by the data manager when executing the generalized software updaterprogram. The listing may additionally specify files contained within thepackage that will be used by the generalized updater to perform theupdating.

A specialized updater program may be provided in the command package. Insuch a case, a package information listing specifying the SoftwareUpdatecommand would specify files contained within the package to be used bythe specialized updater to perform the updating.

After performing the SoftwareUpdate command, the data manager softwaremay record in the database a notation as to whether or not the updatehas been performed successfully. In the case where the data mangersoftware itself is being updated, special steps may need to be taken tomake sure that the update is recorded because updating of the datamanager software may necessitate ceasing execution of the program. Theupdater program may be designed to shut down the data manger softwarebefore updating it and the data manger software may be designed to makea “update pending” entry in the log before being shut down to beupdated. The updater program could be further designed to, and afterperforming the update, restart the data manager software and send it acommand to remove the “update pending” notation and record in thedatabase the status (success or failure) of the update as determined bythe installer. In the case that the update was unsuccessful such thatthe data manager program was unable to be restarted or to receive thecommand from the updater to make a recordation in the database, the“update pending” listing would remain in the database to provideevidence that some error had occurred.

Alternatively, the data manager software would not be instructed to makean “update pending” recording in the database before being shut down toreceive an update. Instead, the updater may be designed so that, in thecase that the update was unsuccessful such that the data manager programwas unable to be restarted or to receive the command to make arecordation in the database, the updater may send a message to NOC 300indicating that the update was unsuccessful and that as a result thedata manager software was inoperative.

Still another example of a command is the “DeleteContent” command. Whenthe package information listing specifies this command, the listing alsoincludes additional information necessary for carrying out the commandin the form of a listing of the identities of the content files thatshould be deleted. In response to this command the data manager softwareacts to delete the indicated file in the manner noted above.

A further example of a command is the “RequestFileStatus” command. Whenthe package information listing specifies this command, the listing alsoincludes additional information necessary for carrying out the commandin the form of a listing of the identities of the content files whosestatus is requested. The listing additionally notes, for each file, theparticular information requested such as the package from which the filearrived, the file's version, the expiration date of the file, whetherthe file's “forced delete” flag is set to true, the last time the filewas accessed, the number of times the file has been accessed, and thelike. In response to this command the data manager software acts toreturn a message to NOC 300 containing the requested information. Therequested information may be collected from the database of EN 500 or byhaving the data manager software be designed to collect or derive therequired information from the appropriate places within the edge node.

Another command may be the “RequestContent” command. This commandindicates a request for the data manager software to return to NOC 300 amessage containing a list of all content files and software packagesstored on the edge node. The request may indicate that the data managersoftware should additionally return the version of content files andsoftware packages. Alternatively, the database of EN 500 would containtitles or identifiers of all software and content files stored on theedge node along with their respective version numbers. In such anembodiment, the data manager may answer the RequestContent command byconsulting the database. When none or only some of the version, title oridentifier information was stored in a database, the data manager mayanswer the command by performing a search of the storage devices of thenode, the search looking for all software and content files. As is knownin the art, such searching could be done by specifying certain searchcriteria such as file attributes to a file search function built in tothe operating system or operating systems running on the variouscomponents of the edge node. Alternatively, custom search code could bebuilt into the data manager software. Once a particular content file orpiece of software were found, its version could be determined usingfunctions built into the system for determining file attributes.Alternatively, custom code for determining versioning information couldbe built into the data manager software.

A further command is the “UpdateSettings” command. When the packageinformation listing specifies this command, the listing also includesadditional information necessary for carrying out the command in theform of an indication of what devices or software of EN 500 should havetheir settings altered, along with a specification of the specificsetting alterations that should be made. In response to this command thedata manager software acts to make the specified alterations to settingsof the specified devices or software. The data manager software could dothis, for example, by making the specified changes to preferences orsettings files associated with the devices or software or by sending,using a method known in the art such as JMS, instructions to the devicesor software to change their own settings. Alternatively, messagingtechniques may be used. It is specifically noted that the specifiedpiece of software could be the data manager software itself, andaccordingly the data manager could alter its own settings.

An additional command is the “RequestSettings” command. When the packageinformation listing specifies this command, the listing also includesadditional information necessary for carrying out the command in theform of an indication of what devices or software of EN 500 should havetheir settings reported, along with a specification of the specificsetting values that are requested. In response to this command the datamanager software acts to report the requested information to NOC 300 viaa message as described above. The data manager software could compilethe information requested by NOC 300 by, for example, reading therequested data from preferences or settings files associated with thedevices or software. Alternatively, the data manager might be programmedto send, using a method known in the art such as JMS, instructions tothe devices or software to report their own settings. The devices orsoftware may be instructed to report their settings to the data managerusing a messaging technique such as JMS.

EN 500 may receive commands such as those noted above via messagesrather than via packages. Such messages may be sent, for example, overback channel 600. Receiving commands via messages may be in lieu of orin addition to receiving them via packages. Using the commands, NOC 300manages and controls EN 500 without human operators.

A user wishing to view content files stored EN 500 of the presentinvention uses a web browser running on his personal computer or otherweb-enabled device to visit a website hosted by a content provider, anLMSP or internet service provider (ISP), or another party. The websitemay be configured to display to the user various media files availableand provide a way for a user to request viewing of a particular mediafile, perhaps by having the user click on an image or button or choose aselection from a pull down menu. The website could be designed so that,in response to the user's request, the user's browser issues anhypertext transfer protocol (http) “get” command to an internetredirection engine (IRE) program running on a general purpose computerlocated at NOC 300 or elsewhere. Alternatively, the web page may bedesigned to issue an http get command to the IRE without the user'sexplicit request. The manner of making such http get commands is knownin the art.

In response to receipt of the get command, the IRE may launch a processwhich, as a first step, would determine the IP address of the user'smachine. This can be done, for example, by examining the headers of theIP packets which comprise the http get command. The process then couldemploy the user's IP address in order to determine which EN or EN serveris best able to meet the users request.

As noted above, NOC 300 may receive from each ENs information concerningthe content files stored there and where in the EN they are stored.Using this information, the IRE can determine for any given edge node orEN server whether or not it contains the content file the user wishes touse. The IRE additionally can determine the distance (network orgeographical) between a given EN or EN server and the user. This can bedone in a number of ways. One way is that the IRE program can haveaccess to a table, database, or the like which notes the relativedistance between a user of a certain IP address (or with a certain IPprefix) and a given EN or EN sever. One way of compiling such a tablewould be to compile it by executing at the various ENs a network utilitysuch as the Unix command “traceroute” to determine the number of networkhops that occur between the edge node and certain user IP addresses (orgroups of IP addresses). Ideally, the traceroute or similar programwould be run remotely. Thus, for example, NOC 300 could remotely requesta particular EN to run traceroute with an input parameter being aspecified IP address such as the IP address of a user's machine. NOC 300may further indicate that the EN should return a message to NOC 300stating number of hops returned by traceroute.

Alternatively, the data manager may be programmed to make use of theLoose Source Route (LSRR) IP protocol which, as is known in the art,allows one to specify the nodes that packets must travel through to getto their destination. Doing so effectively allows one to implementtraceroute-like functionality wherein one may specify both a source anddestination IP address and receive in return the number of hops betweenthe two corresponding nodes.

As another alternative, such a table could be compiled through manualentry of the geographical distances or numbers of hops between certainuser IP addresses (or IP address prefixes) and certain ENs. The tablemay include a specific indication of EN that is known to be nearest toparticular user IP addresses or to groups of IP addresses. For example,a LMSP or ISP which hosts an EN at particular internet access point mayprovide for inclusion in the table an indication of which user IPaddresses have a direct or nearly direct connection, via an LMSP, to aparticular EN.

With these two pieces of information, the IRE process can search for theEN or EN server closest to the user which contains the content file thatthe user requires. Ideally, this will turn out to be an EN or EN serverco-located with or directly connected to the user's ISP or LMSP (e.g.,EN 500A for user A, EN 500B for user B, EN 500C for user C as shown inFIG. 2). The IRE program then commands the user's browser to request,via an LMSP, streaming of the content file from the determined edge nodeor edge node server. As is known in the art, streaming offersfunctionality similar to conventional radio and television broadcast.Rather than having to, for example, download a visual program in itsentirety, a user can watch a streaming file as it is transmitted to him.Accordingly, a user could view the stream using an application, browserplug-in, or the like capable of presenting streamed media, such as, forexample, Real RealPlayer, Microsoft Windows Media Player, or AppleQuickTime Player.

This command to the browser may include an indication of an EN serverupon which the content file exists (perhaps in the form of an IP addressor DNS name) along with the name or identifier of the content file. Inresponse to the browser executing the command, the edge node serverwould provide the user with the requested content file. In some cases,the server would access the file from a dedicated storage device, such ahard disk drive contained within the server. In other cases, the serverwould access the file from a shared disk unit.

Under certain circumstances, more than one server at the EN closest tothe user has on an attached storage unit the requested file. When thissituation arises, the IRE may take into consideration traffic load whendeciding which of these servers to use to answer the user's request. Forexample, the IRE process might keep a log of how many users it has sentto one or add more servers within a given period of time, and use thisinformation to choose for the user the least busy of the servers beingconsidered. In other embodiments, the IRE process may randomly chooseamong the servers with the goal of distributing requests among serversin a way that does not overly burden any particular server.

In other embodiments, the command to the browser may not direct a user'sbrowser to a particular server on an edge node. In such embodiments,rather than decide among the various potential edge node servers, theIRE will instead determine only which closest edge node contains theneeded content file and will leave it to the edge node to determinewhich of its one or more servers should be used to meet the request.

Such functionality may be achieved by commanding the users' browser toaccess a certain component of the determined EN and to indicate to thatcomponent the required file. This could be done by having the commandinclude the IP address or DNS name of the component and the name oridentifier of the required content file. In response to the browserexecuting the command, the edge node component would determine which ofits servers to use. The EN component would then forward the browser tothe chosen server which would, in turn, stream to the user the neededcontent file. Such a component could be implemented using a loadbalancing (Level 4) switch.

The multimedia content processing by EN 500 for live content is nowdescribed.

EN 300 of the present invention may also be used in the distribution oflive streaming content to end users. The content stream is received atdish 502 of EN 300 as radio frequency signals carrying UDP packetsencapsulated within IP packets encapsulated within packets of a formatdesigned for satellite transmission (e.g., a DVB format) and is placedonto VLAN 550 in a manner analogous to that described above in referenceto the receipt of non-live streaming content files. The packets areaddressed, likely in a multicast manner, to one or more servers locatedin EN 500 and would thus arrive at the appropriate streaming servers viaVLAN 550. Alternatively, the packets may be addressed, likely in amulticast manner, to the controller 540. The data manager program ofcontroller 540 may be used to determine which server or servers shouldbe receiving the stream. Such a determination might take into accountusage demand such that the more popular the stream the more servers thatwould be allowed to receive it. The determination of popularity could bemade in a number of ways. For example, the content provider couldinclude within the stream an indication of the stream's predictedpopularity. Such a prediction of popularity might also be sent from NOC300 to the controller of EN 500 via a method such as JMS. Alternatively,the controller might make a guess as to the popularity of a stream basedon factors such as the past popularity of related content, such ascontent from the same content provider or concerning the same topic orgenre. In further embodiments, the controller might determine thepopularity of the stream “on-the-fly”, such that it would determine thenumber of users viewing the stream and adjust the number of serversreceiving the stream accordingly. In either of these cases, controller540 may send a message to NOC 300 over link BC 600 informing of theidentities of the server or servers selected.

Server 510 or controller 540 of EN 500 which received a stream coulddetermine if it were an intended recipient of the stream. One way ofdoing this would be to have the stream include constant or periodicidentification codes which identify the stream. Server 510 or controller540 may have access to a listing provided ahead of time by NOC 300 whichnoted the identification codes corresponding to the streams it was anintended recipient for during a certain time period. Server 510 orcontroller 540 may be programmed to ignore the packets of a stream thatit was not intended to receive.

NOC 300 receives messages from various components of EN 500 informingNOC 300 of which servers are receiving which streams. This knowledge,combined with the above-described knowledge of the distances betweenrequesting user devices and an EN, could be used by the IRE to redirectuser requests for live streams to the appropriate EN in a manneranalogous to the one described above in reference to non-live streamingcontent files. Thus, a user may request a live streaming content filevia a web browser and receive the streams from an EN chosen by the IRE.The user could view the received stream using an application, browserplug-in, or the like, capable of presenting streamed media, such as, forexample, RealPlayer or Apple QuickTime Player. The IRE program mayredirect a user stream request to a load balancer of a particular node,and the load balancer may in turn determine which of the servers in theEN should fulfill the stream request.

While FIGS. 5–7 and related descriptions above illustrate someembodiments of an EN of the present invention, EN configuration may bealtered to meet the specific needs of certain uses, markets, and thelike. For example, an EN designed for use by a larger number of usersmay have a multitude of media servers, but no shared storage or loadbalancer. Each server, having its own storage device, could servecontent files, streaming media, or both. The number of servers to placein the EN could be based on knowledge of the user population the node ismeant for and a determination, perhaps statistical, of how many usersone server can successfully provide for. As an example, it might bedetermined that one server should be put in place for every 500 usersthe node will provide for. In other words, an EN that serves about 2000end users may contain four servers and could be implemented using astandard equipment rack as described above.

An EN designed to provide content to a small number of users (e.g., 500or less subscribers) might have a similar configuration but differ byhaving only a single media server. Such an EN may be implemented in asingle box using a single PC or workstation rather than the rackdescribed above. The PC or workstation may be, for example, a DellPowerEdge running Windows 2000 or a Power Macintosh G4 running OS XServer running media server software such as Real's RealServer orMicrosoft's Windows Media Server. The PC or workstation may contain anetwork interface card, such as a gigabit Ethernet card, for connectingto the LMSP and a card implementing the functionality described abovefor receiving DVB packets via a satellite dish. For example, the Sky2PCfrom Digitra Systems may be used as a satellite interface card. Like therack configuration, the single box implementation could serve contentfiles, streaming media, or both.

An EN may be designed to be mobilized or portable. Such an EN may beimplemented using an equipment rack with one or more servers asdescribed above. Preferably, the equipment rack would be strengthenedusing secure mountings and reinforcing rods and would include worldwidepower connections. Such an EN may be implemented using a PC orworkstation with a satellite interface card as described above. Theseconfigurations allow the EN to be carried easily and require little orno reassembly when placed at a site. Such a portable EN may be used toprovide a temporary EN service at an area that is not served by aregular EN. The portable EN may be connected instantly to a LMSP for thestreaming service.

However, such an EN may or may not be connected to a LMSP for the finaldelivery to end users. When the mobilized EN is connected to a LMSP, theconfiguration may be similar to that of a regular EN as discussed above.However, when there is no LMSP available at an area, the mobilized ENmay be configured to deliver multimedia data directly to end users,without the need for an LMSP. This could be done using a wireless methodsuch as, for example, IEEE 802.11 or a wired method such as Ethernet.

Such wireless capability can be implemented by adding to the EN IEEE802.1-compliant equipment from Lucent Technologies. As an example, inthe case where the EN is implemented using a single PC or workstation, aIEEE 802.11 compliant PCI card may be used in conjunction with routingsoftware. As another example, in the case where the EN is implementedusing an equipment rack, an IEEE 802.11 compliant router may be used.End users would have IEEE 802.11 compliant interfaces in their viewingequipment. When a wired method such as Ethernet is used, the EN may beimplemented using a single PC or workstation with several Ethernet cardsand routing software. When a rack configuration is used, a router may beincluded.

The mobilized EN may be equipped with an integrated display screen toreceive and show live multimedia data to the audience of an event suchas a trade show. Such a “demonstration” edge node may not necessarilyinclude networking hardware for connectivity to an LMSP or directly toend users. As an example, one or more of the servers may be furtherequipped with client viewing software such as, for example, WindowsMedia Player or RealPlayer, and a video card for interfacing with thedisplay screen whereby the client software may interface with the serversoftware and ultimately display multimedia content on the displayscreen. Alternatively, when the rack configuration is used, anadditional PC or workstation may be added to the rack for receivingcontent from one or more of the servers. The additional PC orworkstation would run client software as above and would include anetworking card for interfacing with one or more of the servers and avideo card for interfacing with the display screen. Alternatively, thedemonstration EN may be implemented using a single PC or workstationwith a satellite interface card in a manner similar to that describedabove with reference to the portable EN and the EN for a small userpopulation. However, the single PC or workstation may additionallyinclude a video card for interfacing with the display screen and may notnecessarily include networking hardware for connecting to end users oran LMSP. In the demonstration EN embodiments described herein, thedisplay screen could be a standard computer display such as aVESA-compliant display, an NTSC compatible display, or the like. Thecard could be a PCI card compatible with the chosen display, such as aVESA-compliant card with an HD 15 connector or an NTSC compatible cardwith RCA-type connectors. The demonstrator may have multiple displayscreens, each capable of displaying unique content. An instance of theclient viewing software may be executed and a video card may be includedfor each of the multiple displays.

An EN may be implemented so that its user capacity may be increased ordecreased over time by including a load balancer and a shared storage.Media servers of the EN are usually connected to the load balancer(e.g., L-4 switch) to distribute the load equally to the multipleservers. Since the media servers do not hold the content, the serversmay be added or removed instantly (e.g., on-the-fly) while the EN isoperating. For example, if the number of end users is increased duringthe operation of the EN, the servers may be added instantly. If thenumber of end users is decreased during the operation of the EN, theservers may be removed instantly. As will be evident to those skilled inthe art, such scalability is possible because the load balancer willbalance demand over whatever number of servers exist on the EN, and theshared storage means may be added or removed without affecting theavailability of particular content files. The inclusion of the loadbalancer and shared storage provides additional benefits by allowinguser demands upon the EN to be intelligently spread among the availableservers, thereby preventing the EN from having to worry about whichcontent files should be stored on which particular servers.

Other Management Specialized File Naming System

A protocol will be employed for the naming of content files wherebyexamination of the file name will allow determination of certain dataconcerning the file. CP 100 will be provided with the naming protocoland will responsible for naming content files in accordance with theprotocol before transmitting them to NOC 300. Alternatively, NOC 300will be responsible for assigning files names that are compliant withthe established protocol.

Among the information that may be encoded in the file name generated inaccordance with the protocol are: a description of the content containedwithin the file; the identity of the content provider or contentprovider subgroup; the method of delivery to NOC 300 or EN 500 (e.g.,satellite, wire network, wireless network, FedEx hand delivery); thefacility where the content was encoded; the encoding format (e.g.,RealPlayer); the encoding bit rate; and the identity of the machine orperson who performed the encoding, etc.

For example, the protocol might establish that content file namespossess the format such as“ContentProvider_ContentProviderSubgroup-EncodingFacility_ContentDescription-Bitrate.format”.

For example,“AcmeMedia_FunChannel-SomeProviderNY_LeamingSoccer097-300.rm” indicatesthat the content provider is Acme Media, the content provider subgroupis the Fun Channel, the file was encoded at Acme Media's New Yorkencoding facility, that the content is episode 97 of Learning Soccer,that the file was encoded at 300 Kbps, and that the file format isRealPlayer.

Employment of a naming protocol such as this allows for easy filetracking, maintenance, identification, and the like in the system byallowing a great deal of information concerning a file to be derivedfrom its name alone.

Note that the entire file name need not be assigned a name in accordancewith the naming protocol. Rather, only a portion of a file name may bechosen, as desired, to implement the naming protocol, e.g., the first 10characters of the file name, etc.

Specialized IP Addressing Protocol

As is known, one portion of the IP address assigned to a networkcomponent such as a server, router, workstation, or the like isstipulated by a governing body, while a second portion of the IP addressis chosen by someone such as the network administrator responsible forthe network to which the component is attached. Accordingly, thespecifiable portion of the IP addresses of network components located inNOC 300, EN 500 and elsewhere may be chosen according to a protocol sothat examination of the specifiable portion of a component's IP addresswill allow determination of certain information concerning thecomponent.

Among the information which may be encoded into an IP address accordingto the protocol is information concerning the function, identity,location, hardware, operating system, installed software, hardware orsoftware version, and the like of the network component to which the IPaddress is assigned. For example, as is known in the art, class B IPaddresses take the form of “a.b.c.d” where each of “a”, “b”, “c” and “d”are numbers ranging between 0 and 255, and “a” and “b” are stipulatedwhile “c” and “d” are specifiable.

The protocol might establish a bank of values ranging from 0 to 255wherein for each value there is a corresponding hardware description.For example, code “001” correspond to “RealMedia server: Dell PowerEdge6450, Windows 2000” while code “151” may correspond to “Foundry NetworksServerIron XL Load Balancing L4 Switch”. When assigning a class B IPaddresses to a network component, the protocol may specify that the “c”value be chosen according to the bank of values and that the “d” valuebe chosen to be an identification number for the component. For example,according to the protocol a component may be assigned the IP address of“172.17.151.003” indicating that the component was the third FoundryNetworks ServerIron XL Load Balancing L4 Switch among components whosestipulated IP address portion is “172.17”. Similarly, the component IPaddress of “172.16.001.005” may indicate that the component was thefifth RealMedia server based on a Dell PowerEdge 2450 using the Windows2000 operating system among components whose stipulated IP addressportion is “172.16”.

The functions described above of assigning IP addresses to networkcomponents may be implemented by computer code.

Integrated Network Management System

Two components used in IBN 10, 20 are broadband IP gateway and broadbandreceiver/router. The IP gateway performs the multi-protocolencapsulation of IP datagrams into, for example, MPEG-2 packets fordelivery of IP data over, for example, DVB transport streams. Itseamlessly integrates IP capabilities into existing MPEG-2 videonetworks, such as HFC, satellite, or wireless. The broadband receiverdelivers received content streams to the VLAN's of EN 500. IBN 10, 20utilizes IP gateways in its uplink network to convert IP streaming datato, for example, DVB transport streams and multicast DVB streams throughsatellites to the broadband receivers in EN 500.

In addition to managing traditional IP networks, another challenge is tointegrate the broadband streaming device management with off-shelfnetwork management software (e.g., HP Open View and Spectrum). Theapplication for the integration is referred to as an integrated elementmanager system. The application utilizes simple network managementprotocol (SNMP) and collects data from IP gateways and broadbandreceivers. With the application, operators can easily manage IBN 10, 20from one user friendly system. By tightly integrating these two elementsof IBN 10, 20, IP gateways and broadband receiver, with networkmanagement system, the element manager provides operators an effectiveway to safeguard the quality and reliability of the network. Theintegrated manager system is used in the following four major areas ofthe network management.

System Monitoring:

System monitoring includes data collection, event correlation and alarmmanagement. From the operation console, operators will visualize the IPgateways and broadband receivers up down status through a high-levelgraphic user interface. Operators will be able to navigate to a lowlevel and view current device configuration information as well asdevice performance information. The device configuration informationincludes serial number, version number, location, IP address, Max PIDsservice, satellite frequency setting a list of PID value and itsassociated applications, current signal lock status, etc. The deviceperformance information includes Input BER (bit error rate), Eb/No,Packet throughput, each PID throughput, Lock, Fades, Syn err, etc.

Thresholds will be set on some of monitoring data points. For example,if packet throughput is zero in the receiver, a critical alarm must betriggered immediately in the NMS system indicating the receiver hasstopped processing traffic. If Eb/No drops, the system will alarmoperators the device has problem locking on the signal.

The alarms may be tightly integrated with the alarm notification systemof the off-shelf network management package. It enables the operator totake corrective action promptly. An action process will be integratedinto the alarm system that decides when to generate trouble tickets, whotrouble tickets will be assigned to, etc.

Fault Isolation:

Based on logged events, the system will diagnose system behavior thatmight cause problems and reduce system downtime significantly. Forexample, the system can compare PID values in IP gateways and inbroadband receivers to determine if the cause of no PID throughput inthe receiver is the incorrect PID value in the receiver.

System Configuration and Management:

From an operation console, operators will be able to launch a systemconfiguration screen by selecting one submenu from the off-shelf networkmanagement package. Through the interface of the integrated managersystem, the operator may be able to set the configuration on the IPgateways and broadband receivers. The configuration includes assigningPID, frequency, symbol rate, etc.

Operators may also have the option of upgrading software on selecteddevices automatically. The option is very valuable in a distributednetwork like IBN 10, 20 because the operators manage hundreds andthousands of broadband receivers remotely.

Performance Statistics Collection and Reporting:

Collected data is stored in the database. Integrating IP gateway andbroadband receiver performance data with overall network performancedata provides operators an accurate picture of IBN 10, 20 networkavailability and service availability. Operators may be able to view thedevice problem report, availability report and performance report over aset time period. In addition, they will be able to view the overallnetwork availability and performance report including IP gateway andbroadband receivers' statistics.

The many features and advantages of the present invention are apparentfrom the detailed description, and thus, it is intended by the appendedclaims to cover all such features and advantages of the invention whichfall within the true spirit and scope of the invention.

Furthermore, since numerous modifications and variations will readilyoccur to those skilled in the art, it is not desired that the presentinvention be limited to the exact construction and operation illustratedand described herein, and accordingly, all suitable modifications andequivalents which may be resorted to are intended to fall within thescope of the claims.

1. A scalable edge node that receives content from a Network OperationsCenter (NOC) via a satellite content distribution network anddistributes it via a last mile service provider, the edge nodecomprising: a variable number of media servers, changes duringoperation, to meet changes in demand for data; a shared storage deviceconnected to the media servers; a private Virtual Local Area Network(VLAN) that receives content from the NOC over the satellite contentdistribution network and distributes it to the shared storage device,the private VLAN connected to the media servers and comprising areceiving router and a controller; a public VLAN comprising an outboundrouter connected to the media servers for transmitting content to thelast mile service provider, and a load balancer, connected to thevariable number of media servers, to determine which of the mediaservers connected to the load balancer is best able to meet a user'srequest for content; a firewall; and where the firewall connects boththe public and private VLANs.
 2. The edge node of claim 1, where themedia servers, the load balancer, the shared storage device, the privateVLAN, the outbound router, and the firewall are enclosed in a singleequipment rack.
 3. The edge node of claim 1 where the controller isconfigured to process the content received by the private VLAN.
 4. Theedge node of claim 1 where the controller is configured to executecommands received from the NOC.
 5. The edge node of claim 1 where thecontroller is configured to position content on the edge node.
 6. Amethod for using a number of media servers installed in an edge node todistribute content, received from a Network Operations Center (NOC)through a satellite content distribution network, to a number of usersvia a last mile service provider, comprising: receiving content from theNOC via a private Virtual Local Area Network (VLAN) comprising areceiving router and a controller and connected to the media servers;distributing the content to a shared storage device connected to themedia servers: receiving requests for the content from some or all ofthe users; during edge node operation, adding or removing media serversinstalled in the edge node based on the number of users from whom therequests for content are received; using a load balancer to ascertainthe number of servers presently installed in the edge node; using theload balancer to determine which of the servers are best able to meetthe requests; using the determined servers to meet the requests; andtransmitting the content to the last mile service provider via a publicVLAN comprising an outbound router connected to the media servers andthe load balancer.